Naïve is not a word often – maybe ever – used to describe the Mossad. The agency is after all Israel’s version of the CIA. But the case of Prisoner X, rapidly uncoiling now on websites from Canberra to Tel Aviv, owes a measure of its momentum to an assumption by Israeli spymasters that might be described as child-like in its hopefulness. The assumption was that a nameless prisoner could be placed in the most notorious cell in Israel – a whole prison wing, actually, specially built for the man who killed an Israeli prime minister – and somehow escape attention, even after he died inside it.

The prisoner turned out to be Ben Zygier, also known as Ben Alon, also known as Ben Allen, sometimes as Benjamin Burrows. All were legal names he placed on passports during the 10 years he worked with Mossad, before that very agency abruptly placed him under arrest early in 2010. He died in Cell 15 in December of the same year, hanged in what an official investigation concluded was suicide.

What Zygier — the name on his tombstone – did to bring arrest is not known. Nor is it known what he did for Mossad, though the numerous passports he held from his native Australia suggest possibilities. Agents with dual nationality are useful as scouts, moving freely in enemy countries such as Syria, Lebanon or Iran without the lingering concern that comes with traveling on forged documents. Australia turned out to be particularly helpful; by law, a citizen could legally change his or her name once a year.

Zygier changed his three or four times. The first was after he decided to become an Israeli, in 2000. Many immigrants take a Hebrew name. The country’s founding president, David Ben-Gurion, was born David Grun in Poland. Zygier chose a name that implies steadfastness; Alon is Hebrew for “oak tree.” Why did he change it again? And again? That was the question Australian authorities asked Zygier early in 2010, when a dramatic event prompted a closer look at the use of Australian passports by citizens who also claimed Israel as their nationality. The event was the Jan. 19 assassination of a Hamas arms buyer named Mahmoud Al-Mabouh. The Palestinian was killed in his bed in a luxury hotel in Dubai, United Arab Emirates, by Mossad agents who were exposed, first, on hotel security cameras, and then by their passports. Some were forged, others were valid travel documents issued by Britain, France and other countries, including Australia, where officials were livid that Australian sovereignty was used as cover for a hit.

It’s unknown whether Zygier, who was 34, played any role at all in the Dubai assassination. But even if he did not, the Melbourne native apparently came under scrutiny in Australia as officials scoured the records of dual nationals in the wake of the killing. Zygier was in Australia at the time, studying for a master’s degree. The scrutiny could not have been pleasant, and it was not confined to official channels. After being interrogated by the Australian Security Intelligence Organization, he got a call from a reporter. Jason Koutsoukis indicated in the Sydney Morning Herald that intelligence sources had directed him to three men suspected of using their Australian citizenship as a cover to spy for Israel. Koutsoukis wrote that the men operated a “shell” company in Europe to sell electronic gear to Iran – something that, by several published accounts, Western intelligence agencies have indeed done, in order to sabotage Iran’s nuclear program through the sale of deliberately defective equipment.

When Zygier returned to Israel, his bosses had him arrested, Israeli officials tell TIME. The officials offer no details, but indicated the contract agent no longer had the trust of his employers. Whether Zygier had broken during his interrogation by Australian intelligence, or spoken to reporters, or to anyone else, the Mossad regards any breach of confidentiality as akin to treason. (A senior Israeli legal official told reporters Thursday that Zygier “caused severe damage to the security of the country,” but offered no details.) Zygier was placed in Cell 15, under a fictitious name. His defense attorneys were among the most prestigious in Israel, including one who visited him in jail a day or two before he hanged himself – reportedly in the bathroom of his cell, where there is no video camera. The attorney said he denied all charges. He had been in solitary confinement for months.

The body was sent to Melbourne. His family, including a wife and two children, remain out of sight. The death of an unnamed prisoner was mentioned on a news website, Y-Net, but Israel’s censor soon ordered the story be taken down. A gag order on the case remained in effect until this week, when the Australian Broadcasting Corp. aired a half-hour documentary identifying Zygier and his connection to Mossad. Israeli legislators, who are protected by immunity, then asked the Justice minister about the report on the floor of the Knesset. As the lid threatened to blow off, editors were summoned to a meeting with senior government officials to suppress a story that, thanks to social media and the internet, had already ricocheted around the globe. What came next was a backlash. Wrote Shimon Shiffer in Yediot Ahronoth: “The urgent calling of a meeting of the ‘council of editors’ designed to prevent the media from reporting on the Australian investigation after it had already been covered broadly around the world, portrays our decision-makers as an illiterate band of mafiosos protecting narrow interests and looking to whitewash—rather than protecting the security of the State of Israel.”

By Thursday night, information was coming in torrents. The leading Israeli daily Haaretz quoted an unnamed friend as saying Zygier had confided a decade ago in a bar that he was recruited by Mossad. A Kuwaiti newspaper maintained that Zygier had sold information on the Al-Mabhouh operation to Dubai. But the narrative that appeared to be falling in place had the young agent caught between the intelligence agencies of two nations, both of which he had claimed as his own. Tweeted former Aussie prime minister Malcolm Fraser: “Zygier ‘close to spilling on Israel’ Plausible, most likely cause…”

In a follow up, Australian Broadcasting quoted the host of a Jewish community television program in Melbourne, the city where Zygier grew up, and was buried. “Something went horribly wrong somewhere along the line in the beginning of 2010 where there is the passport issue — the Dubai assassination that occurred, and apparently Ben was put under suspicion as one of the people who might have been involved in that whole affair,” said the host, Henry Greener “….I think it was a very personal thing where Ben did something and it wasn’t well-received by his superiors and he went into jail for it. Unfortunately he didn’t come out alive.”

Karl Vick has been TIME's Jerusalem bureau chief since 2010, covering Israel,the Palestine territories and nearby sovereignties. He worked 16 years at the Washington Post in Nairobi, Istanbul, Baghdad, Los Angeles and Rockville, MD.

I have great respect for the Jewish people, and once thought well of Israel too. Past tense. This is what happens to those who work for Israel, and perhaps often to those who work in any "intelligence" agency. May this cause Israel a great deal more harm; they have earned it in the last several years.